This application is also related to application Ser. No. 396,377 filed Aug. 21, 1989, entitled "A Method And Apparatus For Constructing Circumferentially Prestressed Structures Utilizing A Membrane" which is a continuation of application Ser. No. 06/915,269 filed Oct. 3, 1986 and entitled "A Method And Apparatus For Constructing circumferentially Wrapped Prestressed Structure Utilizing A Membrane," which issued as U.S. Pat. No. 4,879,859, which in turn is a continuation-in-part of application Ser. No. 559,991 filed on Dec. 9, 1983 and entitled "Multi-Purpose Dome Structure And Construction Thereof," which issued as U.S. Pat. No. 4,776,145.
This application is also related to Ser. No. 07/436,479 filed Nov. 14, 1989, entitled "A Method And Apparatus For Constructing Circumferentially Prestressed Structure Utilizing A Membrane Including Seismic Coupling," which is a divisional of application Ser. No. 06/915,269, filed Oct. 3, 1986, which was a continuation-in-part of application Ser. No. 559,911 filed on Dec. 9, 1983.
There is presently pending Ser. No. 07/444,839, filed Dec. 1, 1989, entitled "Automated Accurate Mix Application System For Fiber Reinforced Structures" which is a continuation-in-part of Ser. No. 050,317 filed May 14, 1987, which issued as U.S. Pat. No. 4,884,746 and is entitled "Ripple Free Flow Accurate Mix And Automated Spray System" and Ser. No. 07/434,322 filed Nov. 13, 1989, also entitled "Ripple Free Flow Accurate Mix And Automated Spray System," which is a divisional of Ser. No. 07/050,317, filed May 14, 1987 above.
The field of the present invention is of dome structures and their construction which can be used to contain liquids, solids or gases or to provide temporary or permanent shelter.
There has been a need for the facile construction of dome-type structures, as conventional construction of these structures has proven difficult and costly and the structures themselves have had problems with stability and leakage.
Certain of these conventional structures have utilized inflated membranes. Indeed, inflated membranes have been used for airport structures where the structure consists of the membrane itself. Inflated membranes have also been used to form concrete shells wherein a membrane is inflated, and used as a support form. Concrete is placed over the membrane and the membrane is removed after the concrete has hardened. Conventional systems called "Binishells" are systems of this type. These are constructed by placing metal springs and reinforcing over an uninflated lower membrane. Concrete is placed over the membrane and then the membrane is inflated while the concrete is still soft. An upper membrane is placed over the concrete to prevent it from sliding to the bottom as the inflation progresses. After the concrete has hardened the membranes are typically removed. Literature regarding "Binishells" technology is provided under cover of the disclosure statement submitted. It is noted however that the steel springs of the Binishells cannot be used effectively, or economically, in the spring direction (center line of the spring) to restrain tensile forces in, and prestress the concrete. Only bursting forces inside the spring, transverse to the spring direction, can be retained effectively by the wire spiral since the bursting forces will put the wire spiral in tension along the linear direction of the wire. Besides economic considerations which by themselves militate against using springs as prestressing, springs used in the direction of the spring as tensile members, offer excessive strains and creep to be acceptable as prestressing. This coupled with the fact that the spring would not tension the concrete in the axial or linear direction of the wire and indeed forms a sinusoidal pressure pattern, make the subject invention superior to the Binishells system.